Zooplankton Feeding by the Caribbean Reef-Building Coral Montastrea cavernosa
Porter JW. 1974. Zooplankton Feeding by the Caribbean Reef-Building Coral Montastrea cavernosa. Pages 111-125. In Proceedings of the Second International Coral Reef Symposium. Miami, FL. October, 1974. New Haven, CT. Proceedings of the International Coral Reef Symposium
The feeding behavior and digestion rate of the Caribbean reef-building coral, Montastrea cavernosa, is described as well as a method for the in situ extraction of coral gut contents. Guts were extracted two hours after sunset from M. cavernosa on coral reefs in San Bias, Panama. Zooplankton found in the guts of M. cavernosa include: copepods, amphipods, nemerteans, turbellarians, poiychaetes, nematodes, appendicularians, salps, miscellaneous eggs, and.the larvae of decapods, copepods, polychaetes, cirripedes, bryozoans, and corals. Most of the eaten plankters both by number and by weight are near bottom either demersal (truly bottom dwelling) or meroplanktonic (settling to the bottom at some time in the life cycle), and are preyed upon heavily by corals as they come up off the reef at sunset and presumably also as they settle down at dawn. The zooplankton captured by the coral during the two hour period just after sunset contributes an average of between 1 ug dry weight and 75 ug dry weight per polyp per night on the seven nights sampled. As a cautious estimate, this amount represents between 0.2 per cent and II per cent of the total daily energy requirement of the coral (based on published respiration and caloric conversion rates) in this two hour feeding period alone. Only a weak correlation exists between the amount or kind of zooplankton collected in plankton tows made just after gut extraction and the zooplankton found in the gut. There are several reasons for this: (1) the analysis of the degree of digestion of the zooplankton in the guts indicates that most of the feeding occurs at sunset, two hours before the gut sampling or plankton tow, (2) many of the zooplankton in the guts are demersal and would therefore not be captured in a net towed well above the reef, and (3) these long tentacled corals are extremely effective at capturing zooplankton that might bump into and swim away from a net. Based on the highly variable amount of zooplankton in the guts, and the highly variable amount of zooplankton in the water, corals are probably extremely flexible in their utilization of zooplankton as a source of energy. Since most of the zooplankton in the gut comes from the reef itself, the results point to a tight recycling of nutrients and biomass within the coral reef ecosystem.
- Type
- Conference Proceeding Paper
- Authors
- Porter, James
- Units
- SFCN
- Keywords
- Digestion Rate, Guts, Montastrea cavernosa, reef ecosystem, Tentacles